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Bio Portfolio

Bio Protfolio

Describe the Cell membrane made of a phospholipid bilayer, has specialized proteins embedded in them that serve as transportation routes, selectively permeable, fluid-mosaic model describes components, has cholesterol to fill up space
Describe the Mitochodria found in eukaryotic cells, double membrane, filled with fluid and has a complex internal membrane, inner membranes are very folded, looping back & forth, conducts cellular respiration, has a cristae and a matrix
What is a cristae the shlef part in the mitochondria
What is matrix the fluid part in mitochondria
Describe the Smooth E.R. membranous channel that extends through a cell’s cytoplasm, contains enzymes of synthesis of needed biochemicals, plays a role in synthesis of membrane phospholipids and removes toxins, functions in transport, STEROIDS
Describe the Rough E.R. membranous channel that extends through a cell’s cytoplasm, ribosomes embedded in membranes (proteins manufactured at ribosomes of RER enter intramembranous space within the RER), unctions in transport, PROTEINS
Describe the Golgi Bodies set of flatted but curved saccules, recieves transport vesicles from the ER, concentrates the molecular contents of vesicles and chemically adjusts some molecules in preparation for eventual secretion, new vesicles form from golgi body blebbing
Describe the Vesicles come from the rough ER and the golgi apparatus, made of membrane, two types,
What are the two types of vesicles? Transport Vesicles --> take materials from the golgi or rough ER to other parts of the cell, Secretory Vesicles --> take materials (usually proteins) from the golgi apparatus to the cell wall and release materials to be secreted by exocytosis
Describe the Vacuoles membrane bound organelle, present in plant, fungal, bacteria and animal cells. membrane surrounds a mass of fluid. most functions in intracellular digestion functions in autodigestion
What do Vacuoles do in plant. size? it gives structural support, storage, waste disposal, protection and growth. in plant cells, it is very large,
What do vacuoles do in animals. size? commonly used to temporarily store materials or to transport substances. in animal cells, tends to be small
What is does the fluid in a vacuole contain? consists of waste nutrients and products, many plants use vacuoles to help store water
Describe Lysosomes made by golgi bodies, contain hydrolyic enzymes used for hydrolysis of molecules in cells, have double membrane to give greater protection form enzymes becoming free in the cytoplasm
Nucleus control centre of the cell. Contains nuclear envelope, nuclear pores, nucleolus, chromatin,
Describe nuclear envelope encloses the nucleus and has pores, 2 membranes that keeps reactions going on inside the cell from going on the outside of the cell (phospholipid bilayer)
Describe nuclear pores allows large molecules to pass between the nucleus and the cytoplasm and make fluid of nucleus continuous with cytoplasm, they are large protein complexes
Describe nucleolus visible reign within the nucleoplasm, ribosomal RNA and proteins combine to form sub-units of ribosomes,
Describe chromatin genetic material that is suspended in the nucleoplasm and is made out of DNA and protein. functions: package DNA into smaller volume to fit the cell, strengthen DNA to allow mitosis, to prevent DNA damage, to control gene expression and DNA replication
What are chromosomes Chromosomes are coiled up chromatin for cell division --> 23 pairs
Describe cell wall animal cells lack cell walls, made of cellulose, provides protection for inner parts of the cell, prevents significant change in shape and growth, prevents processes like exocytosis & forces cells to accumulate cellular products in large central vacuoles
Describe Chloroplast has an outer and inner membrane, inner structure consists of two parts --> stroma and grana. Functions in photosynthesis
What is the STROMA? STROMA is the aqueous fluid present with the chloroplasts, where dark reaction of photosynthesis occurs,
What is the GRANA? grana appear as discs under the microscope, and are connected to each other with the help of intergranal lamellae, primary site for the light reaction of photosynthesis
Equation for photosynthesis carbon dioxide + water + energy ---> glucose + oxygen + water
Describe cytoskeleton made of three kinds of protein filaments: actin filaments, intermediate filaments, microtubules. functions: establishes cell shape, provides mechanical strength, provides locomotion, helps chromosome separation in mitosis and meiosis,
What are actin filaments? (aka microfilaments) --> the thinnest filaments of the cytoskeleton, contracts to provide movement by sliding across surface of other proteins to produce a shortened structure
What are intermediate filaments? reinforce shape of cells and fix positions of certain organelles
What are microtubules? extend through cell’s membrane into environment, are linear polymers of tubulin, like conveyor belts inside the cells.
Microtubule functions move vesciles, granules, organelles like mitochondria, join with other proteins to form complex structures like cilia, flagella or centrioles.
Cytoplasm the fluid where organelles remain suspended, fills up the cell. site of many vital biochemical reactions crucial for maintaining life. place where cell expansion and growth takes places. provides a medium in which organelles can remain suspended
Cytoplasm parts cytosol, organelles, cytoplasmic inclusions
What is cytosol part of the cytoplasm that is not occupied by any organelle, gelatinous substance, mainly consists of cytoskeleton filaments, organic molecules, salt and water organelles
What are cytoplasmic inclusions insoluble suspended substances found in cytosol are known as cytoplasmic substances, basically, granules of startch and glycogen
Describe how the polarity of water results in hydrogen bonding H-bonding occurs between water molecules because part of the water molecule is negatively charged, while another part is positively charged.
Describe the role of water as a solvent it will dissolve lots and lots of chemicals. It can do this because it is strongly polar and it is a small molecule and can therefor work its way into the crevices of other molecules and break them apart.
Describe the role of water as a temperature regulator has a high specific heat capacity. Heat must be absorbed to break h-bonds. water absorbs heat from air that is warmer and releases stored heat that is cooler.
Describe the role of water as a lubricant abundance, combined with its properties of cohesion, solvation, and heat capacity, makes water a very valuable lubricant in the bodies of organisms. Example: water in saliva
What is an acid? hemicals that release H+ Examples: vinegar, lemonade, HCl From 0 to 7 ---> lower number = more acidic
What is a base chemicals that release OH- Examples: cleaners, NaOH, blood From 7 to 14 ---> higher number = more basic
what is are Buffers chemicals in our bodies that prevent significant changes in pH. Either pick up or release hydrogen or hydroxide. Example: Bicarbonate
what is Neutralization: when and acid and base join to make water and a salt
Why is pH important? pH is important because a change in pH could be very disastrous. For example, the pH in the intestine is 7.8, if it were to become slighty more acidic, the enzymes that are used to breakdown the food would denature and that process will not happen.
What is Dehydration Synthesis When monomers covalently bond to make a polymer and release a water molecule
What is Hydrolysis When bonds in a polymer break because of the addition of water
What are the 4 biochemicals carbohydrates, lipids, proteins, nucleic acids
What are carbohydrates hydrates of carbon --> empirical formula is CH2O, it includes sugars and polymers of sugars, major source of “fuel” for metabolism, component of nucleic acids
What are 3 forms of carbohydrates? monosaccharide (1 sugar), disaccharide (2 sugars) and polysaccharide (many sugars)
What is a monosaccharide? Monosaccharides are the main fuel source for cells. while simple sugars like ribose and deoxyribose are structural components of DNA, EXAMPLES: glucose, fructose, galactose, molecular formula that is a multiple of CH2O
What are disaccharides often serve as forms of sugar transport (energy storage). Also the form which carbohydrates are transported throughout the body
What are Polysaccharides are formed when many monosaccharides are linked together through many synthesis reactions. Examples: cellulose, starch, glycogen
What is cellulose a straight chain polymer of glucose found in plants. Humans are unable to digest it and it passes through our digestive system. This is called fibre and it is a major structural component of plant cell walls
What is starch a fairly straight chain glucose polymer with a small number of branches. It is found in plants but is digestible by humans. The major form in which the monosaccharide glucose is stored in plants
What is glycogen highly branched polymers of glucose found in animals. It is the major form in which the monosaccharide glucose is store in animals.
What is the covalent bond between two monosaccharides by dehydration synthesis is called... glycosidic linkage
How do plants and animals store sugars? plants store starch in leaves animals store glycogen in liver and muscle cells
What are lipids? Biochemicals that do not freely mix with polar solvents like water. They are the second most important energy molecules for us.
What are properties of lipids hydrophobic, non-polar, stick together, yellowish, slippery
Four types of lipids Fatty acids, neutral fats, phospholipids, steroids
What are fatty acids have a long hydrocarbon chain with a carboxyl gorup at the end. There are two types. Saturated and Unsaturated
What are neutral fats? Three fatty acids and a glycerol are joined by an ester linkage --> ester linkage = a bond between a hydroxyl group and carboxyl group. main function is storage.
What are phospholipids? made of glycerol, 2 fatty acids and a phosphate group. Hydrocarbon tail is hydrophobic but phosphate group forms a hydrophilic head.
What are steroids? on-polar lipids characterized by a carbon skeleton consisting of four fused rings. main form of steroid is cholesterol. It is synthesized in liver and obtained from the diet functions as a structural component of the cell membrane
Functions of lipids stores energy for longer use as composed to carbohydrates, shock absorber, protects vital organs, cell membrane structural components, precursors of hormones, insulation - prevents heat loss
What are proteins? biologically functional molecule that consists of one or more polypeptides each folded and coiled in a specific 3D shape
Monomer/ polymer of a protein? Structure of a protein. monomer = amino acid, polymer = polypeptide. structure: central carbon connected to a hydrogen, an amino group, a carboxyl group, and an “R” group
Functions of proteins Structural Proteins=Collagen-skin resilience, keratin- gives hair strength; Metabolic proteins: enzymes-breaks down things, antibodies-fights infections, hormones-cause reactions in the body
What is a peptide bond? when two amino acids are positioned so that the carboxyl group is adjacent to the amino group of the other, they are joined by dehydration synthesis. When it occurs over and over, it makes a polypeptide. Strong covalent bonds
What does the function of a protein depend on? function of a protein depends on its ability to recognize and bind to some other molecule
Four levels of structures of a protein primary, secondary, tertiary, quaternary
Explain the primary structure of creation of a protein the unique sequence of amino acids determined by genetic information. It dictates the secondary and tertiary structures
Explain the secondary structure of creation of a protein hows various shapes, alpha helix or b pleated sheet. Held together by H-bonds between every forth amino acids
Explain the tertiary structure of creation of a protein because of “R” groups, amino acids cause kinks or bends in the spiral patter. Because of this, segments are brought close together and new bonds (H-bonds, ionic bonds, covalent bonds) form. Also hydrophobic side chains make clusters at core of protein
Explain the primary structure of creation of a protein Not for all proteins, it is multiple polypeptides joining together to become a functional protein ex. hemoglobin
What is it called when a protein loses its shape? called denaturation, caused by heat, pH. heavy metals
What are chaperonins protein molecules that assist in proper folding of other proteins. Doesn’t specify final structure but keeps polypeptide segregated from bad influences
What do Nucleic acids do? store, transmit, and help express hereditary information. Enables living organisms to reproduce their complex components from one generation to the other
What are nucleic acids made of? monomers called nucelotides --> a phosphate group, a sugar, and a nitrogenous base
Two types of nucleic acids DNA and RNA
What is DNA genetic material organisms inherit from their parents
function of DNA Determines order of amino acids in proteins, and thus determines their structure and function, Directs RNA synthesis, sugar is deoxyribose
What is RNA involved in taking the genetic info from the DNA and using it to link together amino acids to make proteins. Provides energy, sugar is ribose
What is a nucleoside? nucleoside is the portion of nucleotide without the phosphate group
What are two types of bases? Pyrimidine - 1 ring: thymine (in DNA), uracil (in RNA) and cytosine, Purine - 2 rings: adenine and guanine
What is ATP? An RNA nucleotide with an adenine base and two aditional phosphate groups, energy currency of the cell, cellular respiration it converts energy of glucose into high energy phosphate group
What is ATP used for? provide energy necessary for energy absorbing reactions in the cell, provide energy to get substances outside, provide energy for cellular metabolism, conduct ion particles across nerve cells
What are the four nitrogenous bases in DNA Adenine, Thymine, Cytosine, Guanine
Describe the structure of DNA double stranded polymer of nucleotide monomers. A monomer has deoxyribose (pentose) sugar, a phosphate group and a nitrogenous base (hydrophobic). has a double helix shape --> makes one full turn every 10 layers of base pairs
What are the four nitrogenous bases in RNA Adenine, Uracil, Cytosine, Guanine
describe RNA structure RNA is a single stranded polymer of nucleotide monomers. A monomer has ribose sugar, a phosphate group and a nitrogenous base (hydrophobic).
When does DNA replication occur? during interphase
First step of DNA replication NA helicase (an enzyme) untwists the double helix at the replication fork (Y shaped region where parental strands are being unwrapped), thus separating the two parental strands and making them available as template strands
Second step of DNA rep Single stranded proteins bind to parental strands as they separate to keep the unpaired DNA from re-pairing
Third step of dna rep short stretch of RNA chain is initially produced and is synthesized by the RNA primase
fourth step of dna rep A new DNA strand forms at the 3’ end of the RNA primer
fifth step of dna rep DNA polymerase II adds DNA nucleotide to the RNA primer and continues adding DNA nucleotides complementary to the parental strand and to the growing end of the new DNA strand --> called elongation (elongates from 5’ to 3’)
sixth step of dna rep (leading strand) On the leading strand, DNA Pol III continuously adds nucleotides to the new complementary strand as the fork progresses ---> needs only one primer
sixth step of dna rep (lagging strand) DNA Pol II work away from the replication fork and it synthesizes discontinuously as a series of Okazaki fragments (elongates from 3’ to 5’)
7th step of dna rep (lagging strand) DNA ligase joins the Okazaki fragments into a continuous DNA strand
What does DNa polymerase do proof reads each nucleotide against its template
what is a mutation? when does it occur A permanent incorrect DNA pair, ccurs after successive replications
Steps to proofreading DNA Enzymes detect damaged DNA nuclease cuts DNA at two points and section is removed polymerase fills in missing nucleotides ligase seals free end of new DNA and old DNA
Why do cells monitor DNA Each cell continuously monitors and repairs its genetic material because repair of damaged DNA is important to the survival of the cell.
What are telemores used for linear DNA. They do not contain genes but multiple repitions of one short nucleotide sequence. It acts as a buffer zone to prevent staggered ends caused by not being able to complete the 5’ end
Major functions of DNA DNA stores genetic information that is used for replication and protein synthesis
Major functions of RNA RNA transports hereditary genetic information (in protein synthesis)
Define Recombinant DNA DNA that has been formed artificially by combining constituents from different organisms
What does Recombinant DNA allow scientists to do? allows scientists to insert a segment of DNA from one organism to a chromosome of another
describe three uses of Recombinant DNA Mass produce medical treatments, Treating diseases, Used in agriculture to make Roundup-ready plants and to incorporate other traits thought useful into food crops.
Example of how recombinant DNA is used to Mass produce medical treatments bacteria producing insulin when the insulin gene is spliced into bacteria)
Example of how recombinant DNA is used to Treat diseases jecting virus that has the DNA to reproduce bone cells into bones to treat bone marrow disease)
What is the purpose of DNA replication? The purpose is to ensure the continuity of hereditary traits (by making new cells)
Where does DNA replication occur? DNA replication occurs within the nucleus. This is also the site of mRNA production, The nucleolus produces rRNA ribosomes
First step of protein synthesis Section of DNA called a gene, puffs up through breaking of H-bonds. This exposes the base sequence of nucleotides.
second step of protein synthesis RNA nucleotides from cytoplasm enter the nucleus and bond to complementary bases on the DNA strand
third step of protein synthesis RNA nucleotides bond together forming the mRNA molecule --> TRANSCRIPTION --> it is the making or mRNA from DNA template.
fourth step of protein synthesis mRNA leaves the nucleus and joins with a ribosome
fifth step of protein synthesis Translation at the ribosomes. synthesis of proteins is initiated by a start codon. Start codon must code for the amino acid methionine
sixth step of protein synthesis Elongation occurs and tRNA carries specific amino acids to ribosome
seventh step of protein synthesis Elongation continues until a terminator (stop) codon is reached.
What occurs during elongation Transfer RNA (tRNA) carries amino acid and anticodon, exposed condons determine which tRNA molecules are required for each sequence, Anticodons pair with codon, amino acids line up and other end. alignment promotes peptide bonds to form. CHAIN CONTINUES
What occurs during termination complemntary tRNA does not transport amino acid. release factor binds to stop codon in the A-site causing addition of water molecule instead of amino acid. ribosome releases mRNA and the protein
How many stop codons? three
Identify the complementary nature of the mRNA codon and the tRNA anti-codon each of the 4 bases (in RNA) only forms H-bonds with one other base. Because of this, you can only find two kinds of base pairings in RNA
What are mutagens and what do they do Mutagens interact with DNA in ways that cause mutations ---> they are physical/chemical agents
two common mutagens most common mutagens are chemicals and radiation
What are mutations changes to the genetic information of a cell. They are responsible for huge diversity of genes found among organisms because mutations are ultimately the source of new genes
two types of mutations: Point mutations and chromosome mutations
What are chromosome mutations involve chromosomes being broken or mislocated during cell division like trisomy 21
What are point mutations a change in a single nucleotide, it is a small scale mutation that can be transmitted to offspring. There are two types of point mutations. There are three types
explain substitutions (mutations) replacement of one nucleotide and partner with another pair of nucleotides
what is a silent mutation a type of substitution where the substituted nucleotide has no effect on the protein because the codon still calls for the right amino acid
what is a missense mutation when the amino acid is changed due to substitution. This may have little effect on the amino acid because they may have same properties
what is a nonsesnse mutation when the substituted nucleotide changes the codon to a stop codon. This causes premature termination and almost always leads to non-functional proteins.
What are Insertions/delations (mutations) additions or loses of nucleotide pairs in a gene. All nucleotides downs stream the deletion or insertion are improperly grouped, resulting in extenive missense usually ending in a nonsense and premature termination
What is a frame shift mutation when the reading frame of the genetic message (the codon) is altered. This occurs when the number of nucleotides inserted or deleted is not a multiple of three.
example of a mutations sickle cell disease
Outer parts of membranes are ___________, insides are __________ hydrophilic, hydrophobic
what is passive transport a mechanism of transport across the membrane is considered passive if it does not require energy stored in ATP
in terms of diffusion what is passive transport? the random movement of particles due to concentration differences. It is a passive process. Molecules diffuse until evenly distributed. Some substances diffuse through membranes as if it wasn’t even there
What are some factors that affect diffusion concentration, temperature, size and shape of molecule, ionic charge, viscosity, movement of medium, solubility and polarity
How does concentration affect diffusion difference in solute concentration between two areas. Greater difference, faster the diffusion
How does temperature affect diffusion increasing temperature allows particles to move more. Increase motion, increases diffusion
How does size and shape of molecule affect diffusion smaller substance diffuse faster because they encounter fewer collisions with other substances. Large molecules do not diffuse across membranes
How does size and ionic charge affect diffusion ions are attracted or repelled into particular directions assisting or hindering diffusion depending on the situation
how does viscosity affect diffusion ower the viscosity (fluid density) of solution, more quickly molecules can move through it. Examples, viscosity of water is less than syrup, therefore diffusion through water occurs more quickly
how does movement of medium affect diffusion currents will aid in diffusion. Cytoplasmic streaming helps disperse molecules
how does solubility and polarity affect diffusion affects particles ability to pass freely through the membrane. Example, water diffuses but because of polarity, it does not pass through non-polar interior of bilayer. Instead it passes through protein channels.
in terms of osmosis what is passive transport? the diffusion of water. Because of water’s polarity, it cannot diffuse through the phospholipid bilayer without the aid of a protein channel.
Why does osmosis occur Water moves to areas with greater concentration gradients to dilute solutes. This equalizes concentration throughout.
Explain osmosis in Isotonic solutions Isotonic solutions are solutions with equal concentrations so water diffuses at steady rate
Explain osmosis in Hypertonic solutions solutions with greater solute concentration when compared to the inside of the cell. Water diffuses out
explain plasmolysis and example hen water leaves the cell by osmosis, thus diluting the solute in it’s environment and concentrating solutes in cytoplasm. Cell shrinks and turgidity decreases Example: Crenation in Red Blood Cells
Explain osmosis in Hypotonic solutions solutions with lesser concentrations of solutes when compared to the inside of the cell. Water diffuses into the cell
explain deplasmolysis and example hen water enters the cell by osmosis resulting in the diltion of the greater solute concentration. This causes a gain in turgidity and swelling in animal cells EXAMPLE: Hemolysis in Red Blood Cells.
What is turgor pressure This is the force the cytoplasm exerts against the inside of the cell membrane. Significant changes in turgidity can affect cell function.
What is osmotic pressure he measure the number of collisions water molecules make against the membrane surface. Greater difference of solute concentration = greater number of collisions = higher osmotic pressure
what is facilitated transport a form of passive transport in which materials are moved across the plasma membrane by a transport protein down their concentration gradient --> does not require energy
what is active transport when substance are transported against the law of diffusion (up a concentration gradient) and therefore requires energy. Example: thyroid gland accumulates iodine need to manufacture hormone thyroxin.
When is vesicle transport used (transport in and out) The largest substances that have to enter or leave a cell use membranous vesicles.
What are the two types of vesicle transport Exocytosis and Endocytosis:
what is Exocytosis cytoplasmic vesicles containing wastes of products for secretion come in contact with a cell membrane and fuse onto it and open the surface, thus spilling the contents (Example in the synaptic gap between neurons)
what is Endocytosis product or food comes near a cell, the cell membrane pinches around it until it forms a vesicle
what is Phagocytosis result of ingestion is the formation of a food vacuole, this fuses with a lysosome. Example Ameba ingesting food
what is Pinocytosis: reduced version of phagocytosis where smaller objects or fluids are ingested and a vesicle is immediately formed
Explain the term, “selectively permeable.” Selectively permeable is used to describe function. It means membranes can select substances that are able to move through them
Define metabolism: the totality of an organisms chemical reactions. It is needed for survival and is a combination of the biochemical reactions and pathways that occur within the cells
define Metabolic pathway rderly step-wise series of chemical reactions from the initial reactants to the final products. One reaction leads to the next. It is highly structured and controlled by enzymes.
why are metabolic pathways used it is not possible in biological systems to have a single reaction that could produce complex molecules from simple reactants
what are catabolic pathways breakdown pathways that release energy breaking down complex molecules to simple compounds. EXAMPLE: Cellular respiration --> glucose breaks down to CO2 and H2O
what are anabolic pathways consume energy to build complicated molecules from simple ones EXAMPLE mino acids synthesized from simple molecules and proteins synthesized from amino acids
what is negative feedback when the concentration product of one step increases high enough to inhibit the first step that is dedicated to its own production
What are enzymes proteins that speed up chemical reactions without being consumed. Act as catalysts
Why do metabolic pathways require enzymes? without them, pathways would be congested because reactions would take too long.
what are Substrates the reactant in an enzymes reaction
what is a coenzyme an organic complex, often containing vitamins that assist enzymatic function. Often either accept or contribute ions to the reactions as they proceed. Without the availability of coenzymes and the particles to be contributed, the reactions will cease.
example of a coenzyme NAD contains the vitamin niacin and transports hydrogen for an assortment of enzymatic reactions.
What is activation energy nergy that must be supplied to cause molecules to react with one another. Enzymes lower activation energy by bringing the substrate molecules together and holding them long enough for reaction to take place
what does the thyroid gland do? Cells of thyroid gland release thyroxin into the blood so it circulates the body. Thyroxin increases the rate that cells consume oxygen. promotes ATP production by cellular respiration, thereby potentially increasing the rate of cell metabolism.
Explain the Lock and Key theory nzyme + Substrate meet during the reaction and fit perfectly like a lock and key.
Explain the Induced fit theory enzyme slightly changes when it binds to the substrates in order to get a tighter grip on the reactants.
What does the induced fit theory do Brings the chemical groups of active sites into positions that enhance their ability to catalyze the chemical reactions. After the reaction, the
How does an enzyme speed up reactions? Lowers activation energy, Provides template, As enzyme holds can stretch molecules towards transition-state form, stressing and bending critical bonds that must be broken, Active site might have best pH, Direct participation of active site
What are cofactors? Non-protein helpers for catalytic activity, may be bound permanently or loosely and reversibly along with the substrate
what are organic cofactors called Organic cofactors as called coenzymes (see above)
Identify the role of vitamins as coenzymes Vitamins are relatively organic molecules that are required in trace amounts in our diet for the synthesis of coenzymes. Vitamins become a part of the coenzyme’s molecular structure.
What happens if we don't have enough vitamins vitamin deficiency, less coenzymes can act with enzymes, thereby there is less enzymatic actions.
Differentiate between the role of enzymes and coenzymes in biochemical reactions. (1) Enzymes function as an organic catalyst to speed a chemical reaction. (2) Coenzymes function as to aid the enzyme in speeding a chemical reaction.
What affects enzyme activity? pH, concentration of substrates, temperature, concentration of enzymes, competitive inhibitors, non-competitive inhibitors
How does pH affect enzyme activity Enzymes work at an optimal pH, for most it is around 6-8 (exceptions are pepsin=3 and trypsin=8). If pH is too low or too high, enzyme denatures.
How does temperature affect enzyme activity The lower the temperature, the lower the rate of reaction. Up to a point, the rate of reaction will increase with the temperature. However, once it hits the optimal temperature, the enzyme will denature. Optimal temperature is about 37
How does concentration of substrates affect enzyme activity If concentration of substrate increases, amount of product will increase. After a certain concentration, the rate will not increase anymore because the enzymes are saturated with substrates and can’t work any faster.
How does concentration of enzymes affect enzyme activity This is what limits the overall rate of reaction. The more enzyme there are, the more product there will be. this rate only levels off if you run out of substrate which is not usually the case.
How does competitive inhibitors affect enzyme activity A molecule that looks like the substrate can compete for space at the active site. This slows down the reaction rate. It can be reversible or irreversible.
How does noncompetitive inhibitors affect enzyme activity The inhibitor binds to another place on the enzyme (not the active site), causing the enzyme to change shape at the active site. This is called allosteric inhibition.
example of a noncompetitive inhibitor. what does this one do? Heavy metals like Lead are non-competitive inhibitors that cause poisoning when they bind irreversibly to enzymes and make them denature.
Mouth receives food, chews it up, moistens it and starts to digest starch
tongue aids digestive process by evaluating ingested material and enabling its further passage.
bolus a ball of food that was manipulated into this shape by the tongue
what does the tongue do during swallowing the tongue pushes bolus to the back of the oral cavity and into the pharynx
teeth purpose of teeth is to chew food into pieces that can easily be swallowed. It is shrouded by a tough layer of enamel, dentine and an inner layer of nerves and blood vessels called pulp.
how many teeth in adult mouth 32 teeth: 8 incisors for biting, 4 canines for tearing, 8 flat premolars for grinding, 12 molars for crushing.
Salivary glands Produce saliva
three sets of salivary glands and location the parotid (below the ears), the sublingual (below the tongue), the submandibular (under the lower jar).
what does saliva contain contains water, mucus, salivary amylase (a hydrolic enzyme that breaks down starch in the presence of water
Pharynx The region between the mouth and the esophagus. It connects to two passageways, the esophagus and the trachea.
Epiglottis covers the glottis, thus blocking the entrance to the larynx
what happens when we swallow the soft palate moves back (covering the opening to the nose), the Trachea moves up under the glottis, thus blocking the opening to the larynx, as the glottis is covered.
Esophagus: A long muscular tube that extends from the pharynx to the stomach.
what does the Esophagus contain both striated muscles and smooth muscles and is lined with mucus membrane attached by connective tissue to the layer of smooth muscles that contain both circular and longitudinal muscle
in the esophagus where are the different muscles found striated muscles are at the top and are active during swallowing. Smooth muscles function in peristalsis to move the bolus down.
Cardiac Sphincter: the sphincter that is connected to the esophagus and stomach. It prevents food from moving up and out of the stomach.
what happens when we vomit reverse peristaltic waves cause the sphincter to relax and the contents of the stomach are propelled upwards.
what is heart burn caused by aused by the cardiac sphincter opening and allowing chyme in the lower end of the esophagus.
stomach thick-walled, J-shaped organ that lies on the left side of the body beneath the diaphragm. It has accordion like folds and a very elastic wall. It has three layers that contract to churn and mix contents.
how often does the stomach mix contents every 20 seconds
function of stomach tores food and begins the digestion of proteins. It usually takes 2 to 6 hours for contents to pass the stomach into the small intestine
what is in the lining of the stomach in its lining it contains gastric glands that produce gastric juice
Gastric juice contains pepsinogen and HCl
what happens when pepsinogen and HCl combine pepsinogen forms pepsin, a hydrolytic enzyme that breaks down proteins into smaller chains of amino acids.
what does HCl do gives the stomach a pH of 3 (highly corrosive) in order to kill bacteria in food and help break it down.
why does the stomach not digest itself it has an inner wall that is protected by a thick layer of mucus that is secreted with mucosal cells.
what happens if HCl penetrates the mucus pepsin starts to digest the stomach lining and an ulcer is formed.
gastric ulcer Gastric ulcers are cause by too much gastric juice, too much nervous stimulation (stree) and bacterial infections that impair the ability of cells to produce mucus.
What is it called when gastric juice mixes with food chyme
Pyloric Sphincter controls the emptying of acid chyme into the first part of the small intestine (called the duodenum)
Duodenum: the first 25 cm of the small intestine. lined with millions of interstitial glands that produce juices containing enzymes that finish the digestion of starch.
What happens at duodenum acid chyme mixes with digestive juices from the pancreas, liver, gallbladder and gland cells
secretions of duodenum peptidases (peptides to amino acids), maltase (maltose to glucose) and others digest disaccharides
liver? what does its secretions do produces bile which is sent to the duodenum via a duct from the gall bladder. Secretions from the liver breakdown fat and peptides.
bile a thick green liquid that contains emulsifying agents called bile salts which break fat into droplets, color comes from by-products of hemoglobin. contains salts which emulsifies fats by breaking it into droplets
functions of liver keeps blood con'c constant, interconversion of nutrients, detoxifies, destroys old RBS, produces urea, manufactures plasma proteins and cholesterol, stores iron and vitamins
function of live in embryos makes red blood cells
disorders of liver Jaundice, Gallstones, Viral hepatitis, cirrhosis
gall bladder stores bile
Pancreas It produces insulin and glucagen. it also sends pancreatic juice to small intestine
insulin a hormone that causes glucose in the blood to be taken up by cells, thereby lowering blood sugar. If you don’t produce enough insulin, you suffer from diabetes
Glucagen: raises the blood glucose concentration
What is in pancreatic juice Sodium bicarbonate, Pancreatic amylase (starch to maltose), Trypsin (protein to peptide), Lipase (fat droplets to glycerol and fatty acids, Nuclease ,
what does sodium bicarbonate do neutralizes that acidity of chyme and makes the small intestine pH basic
small intestine ong convoluted walls that consists of millions of finger like projections called villi. Deals with absorption. In order for nutrients to reach body tissues, it must cross the lining of the alimentary canal.
villi has microvilli (where nutrients are absorbed). As well, each villi contains blood vessels and lymph vessels.
what takes place across the wall of each villus absorption takes place across the wall of each villus (can be passive or active). After absorption, it enters the blood or lymphatic system.
Fats absorbed in the small intestine.. recombine into fat molecules in the epithelial cells of the villus, move into the lacteal of each villus and enter lymphatic system, coated with phospholipids, cholesterol and proteins, thus forming chylomicrons
Amino acids absorbed in the small intestine... enter blood through capillary network , blood vessels from the villi in the small intestine merge to form the hepatic portal vein which leads to the liver, liver removes toxic substances.
large intestine consists of the colon, cecum and rectum
what is the anus Opening of the rectum. function is to dispose of waste products in the body
how does the large intestine connect to the small intestine a T-shaped junction. One arm of the T is the colon, which leads to the rectum. The other end is a pouch called the cecum
cecum ferments ingested material (especially animals that eat a lot of plants)
appendix an extension of the cecum
Colon Functions in the reabsorption of water (from feces) and the absorption of certain vitamins. Feces contains bile pigments, heavy metals and E.Coli
e.coli breaks down some indigestible food and in the process, produce vitamin, amino acids and other growth factors that are in turn absorbed by the colon.
Diarrhea when too much water expelled in the feces. It is caused by infection or stress, and it is a symptom that is actually a body defense against pathogens
Constipations when feces are dry, hard and difficult to expel. Leading cause is dietary fibre.
Rectum end of the digestive tract. It acts as a temporary storage site for fecal matter before it is eliminated from the body through the anal canal.
Where can Salivary amylase be found? What does it promote? Found in the mouth and is secreted by our salivary glands (in saliva). It begins the breakdown of starch into smaller polysaccharides
Where can Pancreatic amylase be found? What does it promote? Found in the pancreas and is secreted by our pancreas. It breaks down starch and polysaccharides into smaller monomers
proteases There is pepsin and trypsin
Where can pepsin be found? What does it promote? irst secreted in the form Pepsinogen in the stomach by the gastric glands. When Pepsinogen and HCl combine, it makes pepsin. It breaks down proteins in smaller polypeptides
Where can trypsin be found? What does it promote? Secreted by the pancreas and is found in the small intestine. It breaks down smaller polypeptides into amino acids or oligopeptides.
Where can lipase be found? What does it promote? Secreted by the pancreas and is found in the small intestine. It freaks down fats into glycerol and fatty acids.
Where can peptidases be found? What does it promote? Aminopeptidase, Tripeptidase, Dipeptidase areSecreted by the small intestine and is found in the small intestine. It further breaks down polypeptides into amino acids.
Where can maltase be found? What does it promote? Secreted by the small intestine and is found there. It takes maltose and breaks it up into glucose and glucose.
Where can nuclease be found? What does it promote? deoxynuclease and ribonuclease are secreted by the pancreas and is found in the small intestine. It works on DNA and RNA respectively, and breaks them down into nucleotides.
Where can phosphateses be found? What does it promote? secreted by the small intestine and found there, it breaks down nucleotides into a base, sugar and phosphate
describe peristalsis imply the wave-like contraction of the smooth muscles in the digestive track. It moves contents along our digestive track. Example: the esophagus moves the bolus down with the help of peristalsis.
Describe the components, pH and digestive actions of salivary juices contains water, mucus and salivary amylase. It has a pH of about 6.9. Inside, it has the enzyme, salivary amylase, which breaks down starch. Mucus lubricates and water moves things around.
Describe the components, pH and digestive actions of gastric juices contains pepsinogen and HCl. When those two combine, it makes pepsin. The HCl in the stomach gives it a pH of about 3. The pepsin in the gastric juices start the breakdown of proteins.
Describe the components, pH and digestive actions of pancreatic juices contains bicarbonate, trypsin, proteases, chymotrypsin, and nucleases (enzymes in inactive form). It has a pH of about 8.
Describe the components, pH and digestive actions of intestinal juices ontains mucus, sodium bicarbonate, water, peptidases, maltase, lactase, and phosphateses. It has a pH of about 8.
Describe the role of water as a component of digestive juices Water plays a role in mucus and saliva and helps to lubricate our digestive track. As well, it keeps our feces moist enough to pass through our alimentary canal.
Describe the role of sodium bicarbonate in pancreatic juices Sodium bicarbonate blocks the action of pepsin and raises the pH to create favorable conditions for the enzymes in the small intestine.
Describe the role of HCl in gastric juice HCl helps to kill unwanted bacteria in the stomach. As well it activates pepsinogen and helps it turn into pepsin.
Describe the role of mucus in gastric juice A thick layer of mucus protects the stomach from digesting itself. If HCl does penetrate the mucus, pepsin starts to digest the stomach lining and an ulcer is formed.
Describe the importance of the pH levels in various regions of the digestive tract. ach area of our digestive tract have different enzymes and all enzymes have different optimal pHs. Because of this, we have various ranges of pH levels.
example of importance of pH in various regions of the digestive track pepsin in the stomach works best at a low pH, while nuclease works best at a higher, more basic pH
Describe how the small intestine is specialized for chemical digestion Enzymes breakdown molecules into smaller polymers or monomers
Describe how the small intestine is specialized for physical digestion Contains bile salts which physically breakdown fats into droplets
Describe how the small intestine is specialized for absorption Villi and microvilli give the small intestine a large surface which promotes absorption by the lymphatic system or the blood vessels.
Describe the functions of E.coli in the colon It breaks down indigestible material, and produces some vitamins and other molecules that can be absorbed by humans.
Arteries thick and highly muscular walls, Located deep within tissues, Carries blood away from the heart
Arterioles all the layers of the artery but on a smaller level. Has a pre-capillary sphincter to prevent overload of the capillaries with high pressure blood
Capillaries Smaller blood vessels, that only allow blood one cell at a time, Walls are one cell thick to allow molecules to pass through easily, Highly branched, Function is to allow the exchange of nutrients and wastes and to exchange oxygen and carbon dioxide
Venules wall consist of the same layers as veins, middle layer is less developed cause the walls to be relatively thin, Blood pressure in the venules is relatively low, alls do not need to be particularly thick or muscular,
Veins They are not very elastic or muscluar, Often located near the surface area and next to the skeletal muscle, Have one way valves which allow blood to flow only towards the heart, Consist of three layers of tissues, blood back to the heart
Subclavian arteries and veins: Originate from the aorta and pass under the clavicle (collarbone) and branch to feed the arms (brachial) and chest wall
Jugular veins Conduct blood out of the head region and do not contain valves. Blood flowing through them is influences by gravity
Carotid artery The match for the jugular veins. It branches off the aortic arch and takes blood to the head. highly specialized with different nerve endings. The carotid artery runs reasonably close to the surface.
Mesenteric arteries: artery branches off the dorsal aorta. It subdivides and goes to the intestines. These arteries feed the organs of the digestive system and the mesenteric vein takes the nutrients away.
Anterior and Posterior Vena Cava: Collects blood from the various veins of the systemic circuit and conduct it back into the right atrium
Pulmonary veins and arteries Part of the pulmonary circuit and is comprised of blood vessels associated with the lungs. pulmonary trunk branches to form right and left arteries. conducts deoxygenated blood from the right ventricle towards the lungs
Hepatic vein: When the blood leaves the liver, it travels through the hepatic vein into the posterior vena cava
Hepatic portal vein Transports blood rich with nutrients directly from the intestines to the liver. At the liver, the blood is detoxified.
Renal arteries and veins Branches off the dorsal aorta. Renal arteries take blood to the kidneys while renal veins take blood away from the kidneys
Iliac arteries and veins When the dorsal aorta gets to the pelvic region, it divides into two iliac arteries, one to go down each leg. The femoral artery is a major branch of the iliac artery and services the large quadriceps muscles of the legs
Coronary arteries and veins: First branches off the aorta and feeds the heart. The heart does not receive the blood that travels through it, instead, it gets blood from the coronary arteries.
Aorta: The major blood vessel carrying oxygenated blood out of the heart. It leaves the left ventricle. Branches from this blood vessel feed all the body systems and tissues except the lungs.
Pulmonary system: Blood is carried from the heart to the lungs. Deoxygenated blood exits the right side of the heart (through pulmonary artery), goes to the lungs, becomes oxygenated and enters the left side of the heart oxygenated (through pulmonary vein).
Systemic system Blood carried from the heart to tissues, muscles and other systems. Oxygenated blood exits the heart at the left side (through Aorta), goes to its destination, becomes deoxygenated, and enters the right side of the heart deoxygenated (through vena cava)
Identify differences in structure and circulation between fetal and adult systems oval opening, arterial duct, umbilical arteries and veins, venous duct
Oval Opening An opening between the two atria, covered by a flap that acts like a valve. Some blood is pumped through the flap and into the left atrium, thus bypassing the pulmonary circuit.
Arterial Duct Connects the pulmonary artery and the aorta. Much of the blood being pumped out of the heart to the lungs will be directed away from the lungs and into the aorta. This bypasses the pulmonary circuit.
Umbilical Arteries and Veins vessels that travel to and from Placenta. Umbilical arteries are grafted to the iliac arteries. It supplies oxygen from the mother to the growing fetus
Placenta a membrane shared by the mother and baby across which gasses, nutrients, and wastes are exchanged
Venous Duct connects the umbillical vein to the vena cava to bring blood back to the baby’s heart. It attaches right at the baby’s liver but bypasses most of the liver. This is why chemicals ingested by the mother can seriously affect the baby.
major components of plasma Water, Plasma Proteins, Salts, Gasses, Nutrients, Wastes, Hormones and Vitamins
water in plasma makes up 50% of blood volume maintains blood pressure and dissolve various particle
plasma proteins maintains osmotic pressure of blood. specific proteins have specific functions EXAMPLE (1) albumins function to maintain osmotic pressure (2) fibrinogen is involved in clotting (3) immunoglobins fighting infections
salts in plasma maintain the body’s blood and osmotic pressure
Gasses in blood gasses O2 and CO2 are found in plasma, plasma transports these gases throughout the body
Nutrients three types of nutrient molecules in plasma are glucose, amino acids, and nucleotides. nutrients are transported from the villi of the small intestine throughout the body
Wastes nitrogenous wastes such as CO2 and NH3 are carried by the plasma to the kidneys. these wastes are then removed from the body in the form of urine
hormones and vitamins Aid in reactions and signaling
Lymph capillaries: Called lacteals, they absorb fats at the intestinal villi and transport them to the blood stream
Lymph veins: Extensive vessels with valves. Takes up excess tissue fluid and returns it to the blood stream
Lymph nodes Nodes are small round structures that are found at certain points along lymphatic vessels. It has a fibrous connective tissue capsule. Nodules are the base unit of nodes
what do lymph nodes contain ontain a sinus (open space) line with lymphocytes and macrophages which purify lymph as it passes through the open spaces.
examples of lymph nodes tonsils, axillary nodes (armpits), Peyer’s patches (in the intestinal wall)
red blood cells bright red to dark purple biconcave disks without nuclei that function to transport O2 and CO2
where are red blood cells made made in the red bone marrow of the skill, ribs, vertebrae, and at the ends of long bones. originate as erythrocyte stem cells in the red bone marrow. these stem cells produce new cells and differentiate. cells lose nuclei and acquire hemoglobin,
what does hemoglobin allow rbs to do red-pigment hemoglobin protein allows cell to acquire oxygen (by the heme iron-containing group) in lungs, and give it up in the tissues
white bloo cells larger, have a nucleus, appears translucent. divided into granular and agranular leukocytes. formed in the red bone marrow. fights infection
Platelets fragments of cells, function to aid in blood clots or coagulate, made in the red bone marrow
Antigen a foreign substance (usually a protein or carbohydrate) that stimulates the release of antibodies to it
Antibodies proteins that combine with antigens to neutralize them
Left and Right atria upper chambers of the heart that receives blood and pumps it into the ventricles
Left and right atria lower chambers of the heart that sends blood to major arteries and veins
Coronary arteries and veins blood vessels that serve the heart itself. Lies on the external surface of the heart where they become capillary beds, venules, cardiac veins, which empty into the right atrium
Anterior and posterior vena cava major vein connected to the right atrium which carries deoxygenated blood
aorta major artery of the body, connected to the left ventricle. Sends oxygenate blood to the systemic circuit
Pulmonary arteries and veins part of the pulmonary system which transports blood to and from the lungs
Pulmonary trunk: immediate artery after the right ventricle. Branches into the left and right pulmonary arteries. Takes deoxygenated blood to the lungs
atrioventricular valves: Supported by strong strings called chordae tendinae, which supports the valve and prevents it from inverting when the heart contracts. Directs blood flow and stops back flow between atria and ventricles
Chordae tendineae strong fibrous strings that supports the atrioventricular valves. It is attached to muscular projections of the ventricular walls, which supports valves and prevents them from inverting during contraction
Semi-lunar valves: directs flow of blood and prevents backward movement between the right ventricle and the pulmonary trunk, and the left ventricle, and aorta.
Septum: a wall inside the heart that separates it into the right and left side
SA node: location and function found in the upper dorsal wall of the right atrium. It initiates the heartbeat and automatically sends out an excitation impulse every 0.85 seconds, which causes the atria to contract
AV node: location and function found in the base of the right atrium very close to the septum. It signals the ventricles to contract by large fibers terminating in the more numerous and smaller purkinje fibers
purkinje fibers: location and function line the heart and causes the ventricles to contract.
Describe the autonomic regulation of the heartbeat by the nervous system The autonomic system has two divisions: Parasympathetic system: causes the heartbeat to slow down. Sympathetic system: causes the heartbeat to speed up. Need for oxygen or blood pressure determine which system is activated.
Hypertension systolic pressure, the highest arterial pressure
Hypotension diastolic pressure, the lowest arterial pressure
Factors that affect and regulate blood pressure Large cross-sectional area of the capillaries, Distance from left ventricle, Thoracic cavity expands during inspiration and aids in flow of venous blood because blood flows in the direction of reduce blood pressure
diastolic BP 60 to 80 mmGH, the pressure that is exerted on the walls of the various arteries around the body in between heart beats when the heart is relaxed. Ventricles are filled with blood
systolic bp 90 to 120 mmGH. amount of pressure that blood exerts on arteries and vessels while the heart is beating. Ventricles are contracting
Nasal Cavity: Basically the nose area that is covered in hairs. Helps to carry the gases to filter air that enters lungs, along with the production of microorganisms.
Pharynx A small muscular tube connecting to the mouth and the esophagus. It is a common passageway for both food and air. It opens up to two passageways
Larynx: It is a cartilaginous organ that is known as the voice box because vocal cords are inside the larynx. At the top is the glottis opening. Functions in sound production
Vocal cords mucus membrane folds supported by elastic ligaments stretched across the glottis
Trachea: flexible tube that connects larynx with bronchi. It functions as a passage of air to bronchi. It is known as the windpipe. held open by C-shaped cartilaginous rings. Cilia in trachea sweep mucus and debris towards the throat to keep the lungs clean.
Bronchi major divisions of the trachea that enters the lungs, it functions as passages of air to each lung. Bronchi contain less and less cartilaginous tubes.
Bronchioles branched tubes that lead from the bronchi to the alveoli, it functions as passages of air to each alveolus. Each bronchiole terminates in an elongate space enclosed by a multitude of air pockets (alveoli)
Alveoli air pockets/sacks that make up the lungs, and gives the lungs a large surface area. One cell thick. lined with lipoprotein that lowers the surface tension and prevents them from closing
Diaphragm dome-shaped horizontal sheet of muscle and connective tissue that forms the floor of the thoracic cavity. When it is relaxed it is dome shaped, when it contracts it lowers
Pleural membranes air-tight membrane that encloses the lungs. 3 parts..
what are three parts of pleural membranes Outer pleural membrane sticks to the ribcage and diaphragm; inner membrane sticks to the lungs and a fluid separates them.
what do pleural membranes do membrane causes the lungs to expand as the ribs go out and up during inspiration caused by negative pressure. Double membrane allows surface of lungs to slide over the body wall easily, without abrasion
what happens if pleural membrane is punctured air is drawn in through the puncture during inhalation putting pressure on the surface (instead of inside) of the lung causing it to collapse. Called pneumothorax
Thoracic cavity chestal region enclose by the ribs and diaphragm. It contains the respiratory organs.
Explain the roles of cilia and mucus in the respiratory tract Found in the trachea. Mucus traps debris in the lungs, and the cilia sweeps the debris upwards towards the throat. Smoking destroys cilia
Explain the relationship between the structure and function of alveoli Alveoli are air-sacs which compose the lungs. It functions as the sitr where external respiration occurs. Alveoli are plentiful. It has a huge cross sectional area; a large surface area is needed for the constant, essential exchange of gases.
first step of inhalation (inspiration) medulla oblongata senses high concentrations of carbon dioxide and hydrogen ions in the blood plasma
second step of inhalation (inspiration) medulla sends nerve impulses to diaphragm and intercostal muscles making them contract
third step of inhalation (inspiration) contraction lifts intercostal muscles up and out, and pulls diaphragm down
fourth step of inhalation (inspiration) volume of lungs increases and creates negative pressure in the cavity
fifth step of inhalation (inspiration) air is drawn in through the trachea
first step of exhalation (expiration) stretch receptors on surface of alveoli detect that the alveoli are stretched open
second step of exhalation (expiration) stretch receptors signal the medulla to stop the contraction of the diaphragm and intercostal muscles
third step of exhalation (expiration) diaphragm relaxes and bows upwards, intercostal muscles move down and in
fourth step of exhalation (expiration) pressure is put on the thoracic cavity and causes the outward movement of air
secondary mechanism Aortic arch and carotid arteries also contain nerve receptors called chemoreceptors that are sensitive to the oxygen content in blood. If critically low, they help initiate response
Describe the external respiration and the conditions diffusion of oxygen into pulmonary arteries and carbon dioxide into alveoli to be exhausted. Conditions at alveoli = 37 deg C, pH = 7.38
Describe the internal respiration and the conditions diffusion of oxygen into tissues and carbon dioxide into blood. Conditions at tissue = 38 deg C, pH at 7.35
dendrite part of a nerve cell which conducts signals towards the the cell body
cell body part of a nerve cell which contains the nucleus
axon part of a nerve cell which conducts signals away from the cell body
axoplasm the cytoplasm within the axon of a neuron
axomembrane responsible for maintaining the axon’s membrane potential. It is the membrane of the cell
Sensory neurons They have long dendrites that extend from receptors towards the CNS and pass through the dorsal root to the cell body. It allows it to take messages from a sense organ to the CNS. It has relatively short axon to relay messages to the next neuron
Motor neurons: Axon is the longest fibre, has short dendrites. Extends from motor neuron’s cell body, located within the CNS throughout the ventral root and conducts impulses to an effect. This allows it to take messages away from the CNS to a muscle fibre or gland
Interneurons Located entirely within the CNS. It has a short axon. Its job is to interconnect nerve cells. It does this by conveying messages between parts of the system.
Resting potential when the neuron is not conducting impulses. Voltage difference across the membrane of the axon is about -60mV. It is when the axoplasm has a slight negative charge. membrane is not permeable.
during resting potential where are the sodium and potassium ions there are more Na+ ions on the outside (in comparison to outside) and there are more K+ ions on the inside (in comparison to the outside).
Action potential: When a nerve is stimulated by an electric shock, pH change, mechanical stimulation, a nerve impulse is generated. When a nerve impulse is generated, a stimulus surpasses the threshold value to disrupt the axomembrane and suddenly make it permeable to Na+
Depolarization (Upswing) Na+ ions flood to the axoplasm through sodium gates. The movement of Na+ ions reverses the electrical difference in the axomembrane. The axoplasm now has a net positive charge of +40mV relative to the outside.
what happens when axoplasm reaches +40mV Na+ gates close and K+ gates open.
Repolarization It is when K+ ions flood to the outside of the axon. This restores the normal polarity of the ion (back to -60mV).
Sodium-potassium pump: protein carrier which pumps Na+ out and K+ in across the membrane. After repolarization (after repolarization = recovery period), these pumps return ions back to their original places so another impulse can take place. These pumps are always working
Recovery period: ight after repolarization. It is when an impulse cannot conduct an impulse because the ions are in the wrong places (Na+ needs to be able to move inside for the impulse to occur, but it is on the outside). This ensures a one-way direction of an impulse
Threshold (“all or none response”) nce a neurons has reached a threshold (-20mV), it sends the impulse through the fibre maximally. No impulse is stronger than another. If there is a stronger stimulus, there are more impulses
Polarity Polarity is important because it was what needs to be changed in order for an impulse to occur
Relate the structure of a myelinated nerve fibre to the speed of implse conduction Impulses in vertebrates because nerve impulses jump from node to node in a myelinated fibre. This is different to non-myelinated fibers because impulses need to depolarize and repolarize each point along the fibre.
how fast does the impulse travel on myelinated fibers vs. nonmyelinated fibers Myelinated fibers travel 200m/s while non-myelinate fibers travel 0.5m/s
nodes of ranvier gaps left between schwann cells
myelin sheath formed by Schwan cells wraping themselves around several times and lay several layers of plasma membrane containing myelin,
saltatory conduction. Impulses traveling through the fiber by jumpin from node to node
Synapse: region between the end of an axon and the cell body or dendrite to which it is attached
Synaptic ending swollen terminal knobs on the ends of axon terminal branches
Presynaptic membrane: the membrane of an axon synaptic ending
Postsynaptic membrane: the membrane of the next neuron just beyond the axon’s synaptic membrane
Synaptic clef: the space between the presynaptic and the postsynaptic membranes
Synaptic vesicle esicles in the axon bulb that contains neurotransmitters and are contained near the surface of synaptic endings
Calcium ions: When an impulse arrives at the end of an axon, depolarization causes Ca gates to open and Ca to flood in. This causes shortening of protein filaments and results in synaptic vesicles fusing with the membrane
Contractile proteins: Contractile proteins hold on to the vesicles and pulls them in when it is time to fuse with the membrane.
Neurotransmitters chemicals that transmit the nerve impulses across a synaptic cleft. They are small molecules. Can be single amino acids, short chains of amino acids or derivatives of proteins
excitatory neurtransmitters These neurotransmitters stimulate the brain. Examples: Acetylcholine, adrenalin, noradrenalin, serotonin, dopamine.
inhibitory neurtransmitters These neurotransmitters calm the brain and help create balance. Examples: GABA, glycine, sometimes serotonin
Receptors Found on the postsynaptic membrane. Control selective ion channels; binding of a neurotransmitter to its specific receptor opens the ion channels.
Acetylcholinesterase (AChe) it is an enzyme that hydrolyzes the neurotransmitter acetylcholine.
Enzymes: deactivate neurotransmitters to prevent them from continually acting on the post synaptic membrane.
first step of impulse travelling across a synapse Nerve impulse travels along the axon and reaches the synaptic ending
second step of impulse travelling across a synapse Nerve impulses change the presynaptic membrane and Ca++ flows into the synaptic ending
third step of impulse travelling across a synapse Ca++ ions cause contractile proteins to pull synaptic vesicles to the inner surface of the presynaptic membrane
fourth step of impulse travelling across a synapse The synaptic vesicle fuses with the presynaptic membrane and by exocytosis, releases neurotransmitters into the synapse
fifth step of impulse travelling across a synapse Neurotransmitters diffuse across the synaptic cleft to do receptors on postsynaptic membrane. Receptors control selective ion channels; binding of a neurotransmitter to its specific receptor site opens the ion channels
sixth step of impulse travelling across a synapse Ion flux changes the voltage of the postsynaptic membrane. Either moves the membrane closer to the threshold voltage required for an action potential (excitatory synapse) or hyper polarizes the membrane (inhibitory synapse)
seventh step of impulse travelling across a synapse Neurotransmitters are quickly deactivated to prevent them from continually acting on the post synaptic membrane.
eigth step of impulse travelling across a synapse Transmission occurs one way because only the ends of axons have synaptic vesicles that are able to release neurotransmitters to affect the potential of the next neuron.
how are transmitters broken down in the synaptic cleft stsynaptic membrane contains enzymes that rapidly inactivate the neurotransmitter. Sometimes, the synaptic ending rapidly reabsorbs the neurotransmitter, possibly for repackaging in a synaptic vesicle or for chemical breakdown
reflex arc an automatic, involuntary response to changes occurring inside or outside the body. It involves the spinal cord and a spinal nerve
first step of reflex arc Receptor generates nerve impulses
second step of reflex arc Impulse moves along sensory neuron toward he cell body and the CNS. The cell body of this sensory neuron is in the dorsal-root ganglion, outside the spinal chord
third step of reflex arc Impulse moves along cell body, along sensory neuron and enters spinal cord dorsally
fourth step of reflex arc Impulse pass to many interneurons
fifth step of reflex arc Impulse pass to a motor neuron in a spinal chord
sixth step of reflex arc Impulse leaves through axon, which leaves spinal chord ventrally
seventh step of reflex arc Impulse travels along the axon to an effector (like a muscle)
eigth step of reflex arc Effector brings response to stimulus
Central Nervous System in the centre, includes the spinal cord an the brain, brain is where nerve impulses are received, coordinated and interpreted. It contains cell bodies
Peripheral Nervous System rest of the nervous system (outside the midline), contains nerves. The nerves of the peripheral nervous system are cranial nerves, spinal nerves, and therefore sensory fibers and motor fibres. 2 parts
Two divisions of the PNS somatic and autonomic nervous system
Somatic Nervous System This system involves nerves sending sensory impulses from receptors to the CNS and send motor impulses from the CNS to the skeletal muscles The fibers of this system come from the middle part of the spinal cord called the thoracic-lumbar
automatic Nervous System (connects to smooth muscles). Its fibers come from the upper and lower part of the spinal cord called the cranial and sacral nerves. It divides into Sympathetic (emergency) Parasympathetic (normal state, usually depresses)
Somatic Nervous System vs. automatic Nervous System Sympathetic promotes active body functions, while parasympathetic controls the opposite. In their activities, the systems help the body maintain homeostasis
what is the sympathetic nervous system associated with? associated with the “Fight or Flight” reaction. (noradrenalin)
what does the fight or flight reaction do directs energy away from digestion, dilate pupils, increases heart rate, increases perspiration, decreases salvation, increases breathing rate, promotes conversion of glycogen to glucose
what is the parasympathetic nervous system associated with? promotes all the internal responses associated with a relaxed state (caused by neurotransmitter acetylcholine).
what does a relaxed state do? pupils contract, energy diverted for digestion of food, heart rate slows
Identify the source gland for adrenaline Source gland: adrenal medulla
adrenaline's role in fight or flight response Increases blood glucose level, increases metabolic rate, Bronchioles dilate, breathing rate increases, blood vessels to the digestive tract and skin contract, skeletal muscles dilate, cardiac muscles contracts more forcefully and heart rate increases
Medulla oblongata Lies closes to the spinal cord, part of the brainstem. the center of the ANS and involved with heart rate, breathing rate, blood pressure, and reflex reactions like coughing, sneezing, vomiting, hiccoughing, ect. initiates fight or flight.
Cerebrum the central processing area of the brain and is where memory is kept, conscious thoughts are made and where a lot of non-reflexive connections and associations are made.
cerebrum structure It is a large, complex region that has its own subdivisions called lobes and areas of specializations within the subdivision. Impulses that require processing before responding are send to this part of the brain.
Thalamus Receives&sorts sensory information from all parts of the body & channels to the cerebrum. Serves as a central relay station for sensory impulses. Receives all sensory impulses except smell
Cerebellum controls balance and complex muscular movement. It is used to ensure that motor impulses provide smooth movements and the body can maintain its sense of balance and coordination
what is the Cerebellum responsible for maintaing normal muscle tone, posture and balance. As well it functions in muscle coordination and makes sure skeletal muscles work together smoothly. It receives information from the inner ear.
hypothalamus maintains the internal enviornment and is the centre for homeostasis. detects adjustments, then initiates nerve responses or releases hormones.
location of hypothalamus located below the thalamus and controls centers for hunger sleep, thirst, body temperature, water balance, and blood pressure. It controls the pituitary gland
Corpus Colosum horizontal connecting piece between the two hemispheres of the brain. It transmits information between the right and the left hemispheres. Because of the corpus colosum, we can confirm the the two sides of the brain function separately.
Pituitary gland as an anterior and posterior lob, both of which extends from the hypothalamus. It deals with hormones
Anterior pituitary gland, how does it work? hypothalamus detects hormones from the A.P.G are required and releases a “releasing hormone” that travels through a short portal system that interconnects with the A.P.G. Release hormones trigger secretion of the required hormone from the A.P.G
Posterior pituitary gland: The hypothalamus produces hormones that are stored and are released by the posterior pituitary nerve tracks.
Meninges: Protective membranes
three types of meninges (1) Closest to the bone: dura mater, tough layer (2) Middle layer: vascularized archnoid layer (3) Next to nerve tissue: pia mater
Differentiate between the functions of the autonomic and somatic nervous systems. conscious or nonconscious The somatic nervous system operates under conscious control; the ANS operates without conscious control
Differentiate between the functions of the autonomic and somatic nervous systems. effectors Somatic nervous system effectors are skeletal muscles, and ANS effectors include cardiac and smooth muscle, and glands.
Differentiate between the functions of the autonomic and somatic nervous systems. response to neurotransmitters The somatic nervous system responds to neurotransmitters as excitation while the ANS response to neurotransmitters is excitation or inhibition.
Kidney organ in the urinary system that produces and excretes urine
Ureter: one of the two muscular tubes that take urine from the kidneys to the urinary bladder by peristaltic contractions
Urethra tube that takes urine from the bladder to the outside; it is longer in males (in males it functions as a sperm carrier)
Urinary balder hollow, muscular organ whose urine is stored before being discharged by way of the urethra
Renal cortex outer portion of the ksidney which include the glomerular capsule and the convoluted tubules
Renal medulla inner portion of the kidney that consists of renal pyramids (collecting ducts and a portion of the loop of the nephron)
Renal pelvis: hollow chamber in the kidney that lies inside the renal medulla and receives freshly prepared urine from the collecting duct
Nephron anatomical and functional unit kidney; Kidney tubule
Glomerulus luster of capillaries surrounded by the bowman's capsule in a nephron, where glomerular filtration takes place
Bowman’s capsule double-walled cup that surrounds the glomerulus at the beginning of the nephron
Afferent arterioles blood vessel that carries blood to the glomerulus
Efferent arterioles carries blood after the glomerulus
Pertibular capillary network: capillary that surrounds a nephron and functions in reabsorption during urine function
Proximal convoluted tubule: highly coiled region of a nephron near the glomerular capsule, where tubular reabsorption takes place
Distal convoluted: highly coiled region of a nephron that is distant from the glomerular capsule where tubular secretion takes place
Collecting duct tube that receives urine from the distal convoluted tubes of several nephrons within a kidney
Loop of Henle portion of the nephron lying between the proximal and distal convoluted tubules that function in water reabsorption. It is primarily involved with water and sodium levels.
Descending limb (Loop of Henle) water leaves because of a continual osmotic gradient in the renal medulla
Ascending limb (Loop of Henle) salt (Na and Cl) passively diffuse out of the lower part but water stays in the ascending limb
Identify the source glands for ADH Source gland: posterior pituitary gland
Relate ADH to the regulation of water and sodium levels in the blood DH increases blood volume when there is a high amount of solute in the blood (low blood volume). It does this by stimulating the kidneys to reabsorb water, by making the distal convoluted tubule and collecting duct more permeable
Relate aldosterone to the regulation of water and sodium levels in the blood Aldosterone increase blood volume when the blood volume is low due to a low sodium level. It does this by causing sodium to be reabsorbed as water is reabsorbed as well
Pressure filtration first step in urine formation. It is when substances from the glomerulus are removed from blood by force, into the porous beginnings of the nephron tubules by the continuos blood pressure.
Selective reabsorption at proximal convoluted tubule, carrier proteins to pump needed materials back into the already hypertonic blood of the pertibular capillaries. Thus molecules like glucose, amino acids and other nutrients are returned into the blood
Reabsorption of water following an osmotic gradient Cells at the descending loop of henle are permeable to water. Surrounding the loop is an envoironment with high concentration as it descends into the medulla region, increasing the amounts of water removed by from the filtrate.
Tubular excretion: Follows as the filtrate passes through the distal convoluted tubule. Substances that are in excess in the blood are pumped out of the pertibular capillaries and into the filtrate.
Metabolic waste substances left over from excretory processes, which cannot be used by the organism
4 types of metabolic wastes Water: dehydration synthesis & respiration, Carbon dioxide: cellular respiration, Salts: neutralization, Urea: protein metabolism, deamination
Describe how the kidneys maintain blood pH if alkaline If the blood pH is below normal (alkaline), the kidneys will start conserving Hydrogen and doesn't prevent the loss of bicarbonate.
Describe how the kidneys maintain blood pH if acidic When the pH is too high (acidic), it does the opposite, it gets rid of Hydrogen and prevent bicarbonate loss.
Scrotum maintains testes at cooler temperature than the abominal cavity. This is necessary for producing viable sperm
Testes tightly coiled tubules called seminiferous tubules which produce sperm and interstitial cells which produce testosterone
seminiferous tubules Inside are sertoli cells that nourish testes that produce sperm. These are pair organs that develop from gonads within abdomen of the fetus. The subsequently descend through a canal into scrotal sacks during the last 2 months of fetal development
Epidiymis ghtly coiled tubules lying just outside the testes; place of maturation and some storage of sperm. This is where sperm becomes mobile
Ductus (Vas) deferens tube that conducts and stores sperm after maturation in the epidiymis. Sperm is propelled into the Vas deferens by muscular contractions
Prostate gland land below the bladder which secretes a milky alkaline fluid that aids the motility of sperm as well it aids in survival of sperm (neutralizes the acidic environment in the vagina).
Cowper’s gland AKA bulbourethral glands. It is a pair of small glands slightly below the prostate gland on either side of the urethra that secretes mucous secretions that produce a lubricating effect.
Seminal vesicles ies at the base of the bladder. It secretes fluid that contains nutrients for sperm at the time of ejaculation
Penis: cylindrical-shaped organ that hands in front of the scrotum. It is the organ of copulation
Urethra conducts sperm
(1) path of sperm from the seminiferous tubules to the urethral opening Seminiferous tubules produce sperm
(2) path of sperm from the seminiferous tubules to the urethral opening epidydimus for sperm maturation
(3) path of sperm from the seminiferous tubules to the urethral opening vas defenses for storage
(4) path of sperm from the seminiferous tubules to the urethral opening ejaculatory duct where seminal vesicles, prostate gland, and Cowpers’ gland release secretions
(5) path of sperm from the seminiferous tubules to the urethral opening out through urethra
Components of seminal fluid secretes nutrients for use of sperm
Components of prostate gland milky alkaline fluid that aids in motility of sperm and neutralizes acidic environment of vagina
Components of cowpers gland lubricating effect
Tail: has microtubule in the characteristic 9+2 pattern of cilia and flagella. Pushes the sperm cell through the fluid allowing it to "swim"
Mid piece: contains microtubules in the characteristic 9+2 pattern of cilia and flagella. Mitochondria are wrapped around the microtubules and provide energy for movement
Head Contains the important part, the nucleus with the genetic information to be passed onto the child. At the very tip of the head is the acrosome cap which contains enzymes needed to penetrate the outer barriers of the egg.
functions of testosterone sex hormone in males, development and function of reproductive organs, Necessary for maturation of sperm, maintains the male secondary productions characteristics (like a beard), muscle strength, Causes oil & sweat glands in the skin to secrete
first step of testosterone regulation hypothalamus secretes GnRH
second step of testosterone regulation Secretion of GnRH triggers anterior pituitary to produce two hormones: FSH and ICSH
third step of testosterone regulation --> FSH ROUTE FSH promotes spermatogenesis in seminiferous tubules. Does this by entering Sertoli cells and causing them to take up more testosterone. This enhances sperm production. Sertoli cells also release the inhibin hormone.
third step of testosterone regulation --> ICSH ROUTE ICSH controls the production of testosterone in interstitial cells
fourth step of testosterone regulation --> FSH ROUTE Inhibin is detected by the hypothalamus and anterior pituitary gland. When it is detected at a high level, the release of GnRH and FSH are reduced, which in turn reduces amount of sperm and inhibin. This is a negative feedback cycle.
fourth step of testosterone regulation --> ICSH ROUTE increased testosterone levels in the blood. When high levels of ICSH are detected by the hypothalamus, production of GnRH are reduced. This is another negative feedback loop.
Ovaries: Two egg shaped structures at each side of the uterus in the pelvic abdominal cavity. It functions are to produce eggs and sex hormones. It has two parts
two parts of ovaries follicles and corpus lutenum
follicles structures in the ovaries that produce the egg, and in particular, the female sex hormones estrogen and progesterone.
corpus lutenum a yellow body that forms in the ovary from a follicle that has discharged its egg. It secretes progesterone
Oviducts function to conduct egg by the fimbraie (towards the uterus) and cilia lining the oviducts and muscular contraction towards the uterus. It is also a location of fertilization and they extend from the uterus to the ovaries
Uterus (womb) function to house the the developing fetus. It is a thick-walled muscular organ about the size and shape of an inverted pear
Endometrium ining of the uterus. It is composed of connective tissue, glands and blood vessels. If pregnancy occurs, it forms the placenta. It has a basal layer and functional layer which varies with the uterine cycle
Cervix: contains opening to uterus, enters into the vagina at nearly a right angle.
Vagina receives penis during sexual intercourse and serves as a birth canal; tube that makes 45-degree angle with the small of the back, can extend
Clitoris organ homologous to the penis, has a shaft of erectile tissue and is capped by pea shaped glands, sexually sensitive organ in that it has sense receptors
functions of estrogen Controls hormonal level in females by exerting feedback control over the anterior pituitary secrettion of FSH so that the follicular phase comes to an end, Causes endometrium to thicken during the proliferative phase, secondary sex characteristics (breast
(1) Ovarian cycle - follicular phase Low levels of female hormones in blood cause menstruation from days 1-5
(2) Ovarian cycle - follicular phase FSH levels increase from days 6-13. Causes follicle to mature. As it matures, it makes more and more estrogen.
(3) Ovarian cycle - follicular phase High levels of estrogen in blood causes hypothalamus to secrete a large amount of GnRH which leads an LH surge at day 13 which causes ovulation at day 14. Negative feedback by estrogen on FSH ends follicular phase
(4) Ovarian cycle - luteal phase Corpus luteum makes increasing amounts of progesterone
(5) Ovarian cycle - luteal phase High progesterone causes negative feedback control over anterior pituitary secretions of LH, causing corpus luteum to degenerate.
(6) Ovarian cycle - luteal phase Lucteal ends, menstruation occurs
(1) Uterine cycle - follicular phase Low levels of female hormones causes menstruation (days 1 to 5) - endometrium breaks down
(2) Uterine cycle - follicular phase Rising levels of estrogen make endometrium thicken and become vascular and glandular (days 6-13 is the proliferative phase)
(3) Uterine cycle - follicular phase Endometrium rebuilds itself
(4) Uterine cycle - luteal phase Progesterone makes endometrium double in thickness (days 15-28)
(5) Uterine cycle - follicular phase Uterine glands mature and release thick mucoid secretions
(6) Uterine cycle - follicular phase As corpus luteum degenerates, progesterone secretion decreases. Causes menstruation to occur again
positive feedback mechanism involving oxycotin made in the hypothalamus and stored in the posterior pituitary causes the uterus to contract is used to artificially induce labour. also stimulates the release of milk. Contraction of the uterus causes more oxycotin to be secreted, thus, positive feedback
hormonal changes that occur as a result of implantation - Placenta Placenta produces human chorionic gonadotropin (HCG), HCG maintains the corpus luteum until the placenta begins its own production of progesterone and estrogem
hormonal changes that occur as a result of implantation - estrogen Estrogen and progesterone function as to shut down the anterior pituitary so that no new follicles mature and they maintain the lining of the uterus so that the corpus luteum is not needed.
Created by: db5k